What characterizes a balanced chemical equation?

A balanced chemical equation is defined by having equal numbers of each type of atom present on both sides of the equation, ensuring that the law of conservation of mass is upheld. This means that during a chemical reaction, atoms are neither created nor destroyed; they are simply rearranged to form products. Therefore, the counts of each element must match before and after the reaction takes place.

While showing an equal mass of reactants and products relates to the conservation of mass, it does not specifically address the balancing of individual atoms, which is the central focus of a balanced chemical equation. The representation of substances in gaseous states, or the inclusion of catalysts, does not pertain to the fundamental requirement of balancing the equation in terms of atom counts. Thus, the defining characteristic is that both sides of the equation must contain the same number of each type of atom.